1
|
Williams CL, Ponganis PJ. Diving physiology of marine mammals and birds: the development of biologging techniques. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200211. [PMID: 34121464 PMCID: PMC8200650 DOI: 10.1098/rstb.2020.0211] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2021] [Indexed: 11/12/2022] Open
Abstract
In the 1940s, Scholander and Irving revealed fundamental physiological responses to forced diving of marine mammals and birds, setting the stage for the study of diving physiology. Since then, diving physiology research has moved from the laboratory to the field. Modern biologging, with the development of microprocessor technology, recorder memory capacity and battery life, has advanced and expanded investigations of the diving physiology of marine mammals and birds. This review describes a brief history of the start of field diving physiology investigations, including the invention of the time depth recorder, and then tracks the use of biologging studies in four key diving physiology topics: heart rate, blood flow, body temperature and oxygen store management. Investigations of diving heart rates in cetaceans and O2 store management in diving emperor penguins are highlighted to emphasize the value of diving physiology biologging research. The review concludes with current challenges, remaining diving physiology questions and what technologies are needed to advance the field. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
Collapse
Affiliation(s)
- Cassondra L. Williams
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Paul J. Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| |
Collapse
|
2
|
Borque-Espinosa A, Ferrero-Fernández D, Capaccioni-Azzati R, Fahlman A. Lung function assessment in the Pacific walrus ( Odobenus rosmarus divergens) while resting on land and submerged in water. J Exp Biol 2021; 224:jeb227389. [PMID: 33188062 DOI: 10.1242/jeb.227389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 11/09/2020] [Indexed: 11/20/2022]
Abstract
In the present study, we examined lung function in healthy resting adult (born in 2003) Pacific walruses (Odobenus rosmarus divergens) by measuring respiratory flow ([Formula: see text]) using a custom-made pneumotachometer. Three female walruses (670-1025 kg) voluntarily participated in spirometry trials while spontaneously breathing on land (sitting and lying down in sternal recumbency) and floating in water. While sitting, two walruses performed active respiratory efforts, and one animal participated in lung compliance measurements. For spontaneous breaths, [Formula: see text] was lower when walruses were lying down (e.g. expiration: 7.1±1.2 l s-1) as compared with in water (9.9±1.4 l s-1), while tidal volume (VT, 11.5±4.6 l), breath duration (4.6±1.4 s) and respiratory frequency (7.6±2.2 breaths min-1) remained the same. The measured VT and specific dynamic lung compliance (0.32±0.07 cmH2O-1) for spontaneous breaths were higher than those estimated for similarly sized terrestrial mammals. VT increased with body mass (allometric mass-exponent=1.29) and ranged from 3% to 43% of the estimated total lung capacity (TLCest) for spontaneous breaths. When normalized for TLCest, the maximal expiratory [Formula: see text] ([Formula: see text]exp) was higher than that estimated in phocids, but lower than that reported in cetaceans and the California sea lion. [Formula: see text]exp was maintained over all lung volumes during spontaneous and active respiratory manoeuvres. We conclude that location (water or land) affects lung function in the walrus and should be considered when studying respiratory physiology in semi-aquatic marine mammals.
Collapse
Affiliation(s)
- Alicia Borque-Espinosa
- Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain
- Universitat de València, Av. de Blasco Ibáñez 13, 46010 Valencia, Spain
| | | | | | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain
- Global Diving Research, Inc., Ottawa, ON, Canada, K2J 5E8
| |
Collapse
|
3
|
Fang Y, Gu Y, Zhao C, Lv Y, Qian J, Zhu L, Yuan N, Zhang S, Wang L, Li M, Zhang Q, Xu L, Wei W, Li L, Ji L, Gao X, Zhang J, Shen Y, Chen Z, Wang G, Dai K, Wang J. Impact of supervised beego, a traditional Chinese water-only fasting, on thrombosis and haemostasis. BMJ Nutr Prev Health 2021; 4:4-17. [PMID: 34308107 PMCID: PMC8258074 DOI: 10.1136/bmjnph-2020-000183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022] Open
Abstract
Beego is a traditional Chinese complete water-only fasting practice initially developed for spiritual purposes, later extending to physical fitness purposes. Beego notably includes a psychological induction component that includes meditation and abdominal breathing, light body exercise and ends with a specific gradual refeeding program before returning to a normal diet. Beego has regained its popularity in recent decades in China as a strategy for helping people in subhealthy conditions or with metabolic syndrome, but we are unaware of any studies examining the biological effects of this practice. To address this, we here performed a longitudinal study of beego comprising fasting (7 and 14 day cohorts) and a 7-day programmed refeeding phase. In addition to detecting improvements in cardiovascular physiology and selective reduction of blood pressure in hypertensive subjects, we observed that beego decreased blood triacylglycerol (TG) selectively in TG-high subjects and increased cholesterol in all subjects during fasting; however, the cholesterol levels were normalised after completion of the refeeding program. Strikingly, beego reduced platelet formation, activation, aggregation and degranulation, resulting in an alleviated thrombosis risk, yet maintained haemostasis by sustaining levels of coagulation factors and other haemostatic proteins. Mechanistically, we speculate that downregulation of G6B and MYL9 may influence the observed beego-mediated reduction in platelets. Fundamentally, our study supports that supervised beego reduces thrombosis risk without compromising haemostasis capacity. Moreover, our results support that beego under medical supervision can be implemented as non-invasive intervention for reducing thrombosis risk, and suggest several lines of intriguing inquiry for future studies about this fasting practice (http://www.chictr.org.cn/index.aspx, number, ChiCTR1900027451).
Collapse
Affiliation(s)
- Yixuan Fang
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
- State Key Laboratory of Radiation Medicine and Radioprotection, Soochow University, Suzhou, China
| | - Yue Gu
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Chen Zhao
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Yaqi Lv
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Jiawei Qian
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Lingjiang Zhu
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Na Yuan
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
- State Key Laboratory of Radiation Medicine and Radioprotection, Soochow University, Suzhou, China
| | - Suping Zhang
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
- State Key Laboratory of Radiation Medicine and Radioprotection, Soochow University, Suzhou, China
| | - Li Wang
- Soyo Center, Soochow University, Suzhou, China
- Department of Community Nursing, Soochow University, Suzhou, China
| | - Mengli Li
- Soyo Center, Soochow University, Suzhou, China
- Department of Community Nursing, Soochow University, Suzhou, China
| | - Qing Zhang
- Soyo Center, Soochow University, Suzhou, China
- Department of Kinesiology, Soochow University, Suzhou, China
| | - Li Xu
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Wen Wei
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Lei Li
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Li Ji
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Xueqin Gao
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Jingyi Zhang
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
- Department of Pharmacology, Soochow University, Suzhou, China
| | - Yueping Shen
- Soyo Center, Soochow University, Suzhou, China
- Department of Epidemiology and Biostatistics, Soochow University, Suzhou, China
| | - Zixing Chen
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
| | - Guanghui Wang
- Department of Pharmacology, Soochow University, Suzhou, China
| | - Kesheng Dai
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- State Key Laboratory of Radiation Medicine and Radioprotection, Soochow University, Suzhou, China
| | - Jianrong Wang
- Hematology Center of Cyrus Tang Medical Institute, Soochow University, Suzhou, China
- Soyo Center, Soochow University, Suzhou, China
- State Key Laboratory of Radiation Medicine and Radioprotection, Soochow University, Suzhou, China
| |
Collapse
|
4
|
Denk M, Fahlman A, Dennison-Gibby S, Song Z, Moore M. Hyperbaric tracheobronchial compression in cetaceans and pinnipeds. J Exp Biol 2020; 223:jeb217885. [PMID: 32041809 DOI: 10.1242/jeb.217885] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/31/2020] [Indexed: 11/20/2022]
Abstract
Assessment of the compressibility of marine mammal airways at depth is crucial to understanding vital physiological processes such as gas exchange during diving. Very few studies have directly assessed changes in cetacean and pinniped tracheobronchial shape, and none have quantified changes in volume with increasing pressure. A harbor seal, gray seal, harp seal, harbor porpoise and common dolphin were imaged promptly post mortem via computed tomography in a radiolucent hyperbaric chamber. Volume reconstructions were performed of segments of the trachea and bronchi of the pinnipeds and bronchi of the cetaceans for each pressure treatment. All specimens examined demonstrated significant decreases in airway volume with increasing pressure, with those of the harbor seal and common dolphin nearing complete collapse at the highest pressures. The common dolphin bronchi demonstrated distinctly different compression dynamics between 50% and 100% lung inflation treatments, indicating the importance of air in maintaining patent airways, and collapse occurred caudally to cranially in the 50% treatment. Dynamics of the harbor seal and gray seal airways indicated that the trachea was less compliant than the bronchi. These findings indicate potential species-specific variability in airway compliance, and cessation of gas exchange may occur at greater depths than those predicted in models assuming rigid airways. This may potentially increase the likelihood of decompression sickness in these animals during diving.
Collapse
Affiliation(s)
- Michael Denk
- Kansas State University College of Veterinary Medicine, Manhattan, KS 66502, USA
| | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain
| | | | - Zhongchang Song
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, People's Republic of China
| | - Michael Moore
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| |
Collapse
|
5
|
Hermann-Sorensen H, Thometz NM, Woodie K, Dennison-Gibby S, Reichmuth C. In Vivo Measurements of Lung Volumes in Ringed Seals: Insights from Biomedical Imaging. J Exp Biol 2020:jeb.235507. [PMID: 34005800 DOI: 10.1242/jeb.235507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/11/2020] [Indexed: 11/20/2022]
Abstract
Marine mammals rely on oxygen stored in blood, muscle, and lungs to support breath-hold diving and foraging at sea. Here, we used biomedical imaging to examine lung oxygen stores and other key respiratory parameters in living ringed seals (Pusa hispida). Three-dimensional models created from computed tomography (CT) images were used to quantify total lung capacity (TLC), respiratory dead space, minimum air volume, and total body volume to improve assessments of lung oxygen storage capacity, scaling relationships, and buoyant force estimates. Results suggest that lung oxygen stores determined in vivo are smaller than those derived from postmortem measurements. We also demonstrate that-while established allometric relationships hold well for most pinnipeds-these relationships consistently overestimate TLC for the smallest phocid seal. Finally, measures of total body volume reveal differences in body density and net vertical forces in the water column that influence costs associated with diving and foraging in free-ranging seals.
Collapse
Affiliation(s)
- Holly Hermann-Sorensen
- University of California Santa Cruz. Department of Ocean Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
| | - Nicole M Thometz
- University of San Francisco, Department of Biology. 2130 Fulton Street, San Francisco, CA 94117, USA
- University of California Santa Cruz. Institute of Marine Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
| | - Kathleen Woodie
- Alaska SeaLife Center, 301 Railway Ave, Seward, AK 99664, USA
| | | | - Colleen Reichmuth
- Alaska SeaLife Center, 301 Railway Ave, Seward, AK 99664, USA
- University of California Santa Cruz. Institute of Marine Sciences, 115 McAllister Way, Santa Cruz CA 95060, USA
| |
Collapse
|
6
|
Allen KN, Vázquez-Medina JP. Natural Tolerance to Ischemia and Hypoxemia in Diving Mammals: A Review. Front Physiol 2019; 10:1199. [PMID: 31620019 PMCID: PMC6763568 DOI: 10.3389/fphys.2019.01199] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 09/03/2019] [Indexed: 12/15/2022] Open
Abstract
Reperfusion injury follows ischemia/reperfusion events occurring during myocardial infarction, stroke, embolism, and other peripheral vascular diseases. Decreased blood flow and reduced oxygen tension during ischemic episodes activate cellular pathways that upregulate pro-inflammatory signaling and promote oxidant generation. Reperfusion after ischemia recruits inflammatory cells to the vascular wall, further exacerbating oxidant production and ultimately resulting in cell death, tissue injury, and organ dysfunction. Diving mammals tolerate repetitive episodes of peripheral ischemia/reperfusion as part of the cardiovascular adjustments supporting long duration dives. These adjustments allow marine mammals to optimize the use of their body oxygen stores while diving but can result in selectively reduced perfusion to peripheral tissues. Remarkably, diving mammals show no apparent detrimental effects associated with these ischemia/reperfusion events. Here, we review the current knowledge regarding the strategies marine mammals use to suppress inflammation and cope with oxidant generation potentially derived from diving-induced ischemia/reperfusion.
Collapse
|
7
|
Hindle AG, Allen KN, Batten AJ, Hückstädt LA, Turner-Maier J, Schulberg SA, Johnson J, Karlsson E, Lindblad-Toh K, Costa DP, Bloch DB, Zapol WM, Buys ES. Low guanylyl cyclase activity in Weddell seals: implications for peripheral vasoconstriction and perfusion of the brain during diving. Am J Physiol Regul Integr Comp Physiol 2019; 316:R704-R715. [PMID: 30892912 PMCID: PMC6620652 DOI: 10.1152/ajpregu.00283.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 01/06/2023]
Abstract
Nitric oxide (NO) is a potent vasodilator, which improves perfusion and oxygen delivery during tissue hypoxia in terrestrial animals. The vertebrate dive response involves vasoconstriction in select tissues, which persists despite profound hypoxia. Using tissues collected from Weddell seals at necropsy, we investigated whether vasoconstriction is aided by downregulation of local hypoxia signaling mechanisms. We focused on NO-soluble guanylyl cyclase (GC)-cGMP signaling, a well-known vasodilatory transduction pathway. Seals have a lower GC protein abundance, activity, and capacity to respond to NO stimulation than do terrestrial mammals. In seal lung homogenates, GC produced less cGMP (20.1 ± 3.7 pmol·mg protein-1·min-1) than the lungs of dogs (-80 ± 144 pmol·mg protein-1·min-1 less than seals), sheep (-472 ± 96), rats (-664 ± 104) or mice (-1,160 ± 104, P < 0.0001). Amino acid sequences of the GC enzyme α-subunits differed between seals and terrestrial mammals, potentially affecting their structure and function. Vasoconstriction in diving Weddell seals is not consistent across tissues; perfusion is maintained in the brain and heart but decreased in other organs such as the kidney. A NO donor increased median GC activity 49.5-fold in the seal brain but only 27.4-fold in the kidney, consistent with the priority of cerebral perfusion during diving. Nos3 expression was high in the seal brain, which could improve NO production and vasodilatory potential. Conversely, Pde5a expression was high in the seal renal artery, which may increase cGMP breakdown and vasoconstriction in the kidney. Taken together, the results of this study suggest that alterations in the NO-cGMP pathway facilitate the diving response.
Collapse
Affiliation(s)
- Allyson G Hindle
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Kaitlin N Allen
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Annabelle J Batten
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Luis A Hückstädt
- Department of Ecology and Evolutionary Biology, University of California , Santa Cruz, California
| | - Jason Turner-Maier
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - S Anne Schulberg
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Jeremy Johnson
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Elinor Karlsson
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Kerstin Lindblad-Toh
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University , Uppsala , Sweden
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California , Santa Cruz, California
| | - Donald B Bloch
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
- Division of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Warren M Zapol
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Emmanuel S Buys
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| |
Collapse
|
8
|
Ponganis PJ. State of the art review: from the seaside to the bedside: insights from comparative diving physiology into respiratory, sleep and critical care. Thorax 2019; 74:512-518. [PMID: 30826734 DOI: 10.1136/thoraxjnl-2018-212136] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/20/2019] [Accepted: 01/28/2019] [Indexed: 11/04/2022]
Abstract
Anatomical and physiological adaptations of animals to extreme environments provide insight into basic physiological principles and potential therapies for human disease. In that regard, the diving physiology of marine mammals and seabirds is especially relevant to pulmonary and cardiovascular function, and to the pathology and potential treatment of patients with hypoxaemia and/or ischaemia. This review highlights past and recent progress in the field of comparative diving physiology with emphasis on its potential relevance to human medicine.
Collapse
Affiliation(s)
- Paul J Ponganis
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
9
|
Lillie MA, Vogl AW, Raverty S, Haulena M, McLellan WA, Stenson GB, Shadwick RE. Controlling thoracic pressures in cetaceans during a breath-hold dive: importance of the diaphragm. J Exp Biol 2017; 220:3464-3477. [DOI: 10.1242/jeb.162289] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/17/2017] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Internal pressures change throughout a cetacean's body during swimming or diving, and uneven pressures between the thoracic and abdominal compartments can affect the cardiovascular system. Pressure differentials could arise from ventral compression on each fluke downstroke or by a faster equilibration of the abdominal compartment with changing ambient ocean pressures compared with the thoracic compartment. If significant pressure differentials do develop, we would expect the morphology of the diaphragm to adapt to its in vivo loading. Here, we tested the hypothesis that significant pressure differentials develop between the thoracic and abdominal cavities in diving cetaceans by examining diaphragms from several cetacean and pinniped species. We found that: (1) regions of cetacean diaphragms possess subserosal collagen fibres that would stabilize the diaphragm against craniocaudal stretch; (2) subserosal collagen covers 5–60% of the thoracic diaphragm surface, and area correlates strongly with published values for swimming speed of each cetacean species (P<0.001); and (3) pinnipeds, which do not locomote by vertical fluking, do not possess this subserosal collagen. These results strongly suggest that this collagen is associated with loads experienced during a dive, and they support the hypothesis that diving cetaceans experience periods during which abdominal pressures significantly exceed thoracic pressures. Our results are consistent with the generation of pressure differentials by fluking and by different compartmental equilibration rates. Pressure differentials during diving would affect venous and arterial perfusion and alter transmural pressures in abdominal arteries.
Collapse
Affiliation(s)
- Margo A. Lillie
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - A. Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Stephen Raverty
- Animal Health Centre, 1767 Angus Campbell Road, Abbotsford, BC, Canada V3G 2M3
| | - Martin Haulena
- Vancouver Aquarium Marine Science Centre, PO Box 3232, Vancouver, BC, Canada V6G 3E2
| | - William A. McLellan
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | | | - Robert E. Shadwick
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| |
Collapse
|
10
|
Fahlman A, Moore MJ, Garcia-Parraga D. Respiratory function and mechanics in pinnipeds and cetaceans. J Exp Biol 2017; 220:1761-1773. [DOI: 10.1242/jeb.126870] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ABSTRACT
In this Review, we focus on the functional properties of the respiratory system of pinnipeds and cetaceans, and briefly summarize the underlying anatomy; in doing so, we provide an overview of what is currently known about their respiratory physiology and mechanics. While exposure to high pressure is a common challenge among breath-hold divers, there is a large variation in respiratory anatomy, function and capacity between species – how are these traits adapted to allow the animals to withstand the physiological challenges faced during dives? The ultra-deep diving feats of some marine mammals defy our current understanding of respiratory physiology and lung mechanics. These animals cope daily with lung compression, alveolar collapse, transient hyperoxia and extreme hypoxia. By improving our understanding of respiratory physiology under these conditions, we will be better able to define the physiological constraints imposed on these animals, and how these limitations may affect the survival of marine mammals in a changing environment. Many of the respiratory traits to survive exposure to an extreme environment may inspire novel treatments for a variety of respiratory problems in humans.
Collapse
Affiliation(s)
- Andreas Fahlman
- Fundación Oceanográfic de la Comunidad Valenciana, Gran Vía Marques del Turia 19, Valencia 46005, Spain
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
| | - Michael J. Moore
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Daniel Garcia-Parraga
- Fundación Oceanográfic de la Comunidad Valenciana, Gran Vía Marques del Turia 19, Valencia 46005, Spain
- Oceanográfic-Avanqua, Ciudad de las Artes y las Ciencias, Valencia 46013, Spain
| |
Collapse
|
11
|
Gerlinsky CD, Rosen DAS, Trites AW. Sensitivity to hypercapnia and elimination of CO2 following diving in Steller sea lions (Eumetopias jubatus). J Comp Physiol B 2014; 184:535-44. [PMID: 24604293 DOI: 10.1007/s00360-014-0819-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 02/05/2014] [Accepted: 02/14/2014] [Indexed: 11/28/2022]
Abstract
The diving ability of marine mammals is a function of how they use and store oxygen and the physiological control of ventilation, which is in turn dependent on the accumulation of CO2. To assess the influence of CO2 on physiological control of dive behaviour, we tested how increasing levels of inspired CO2 (hypercarbia) and decreasing inspired O2 (hypoxia) affected the diving metabolic rate, submergence times, and dive recovery times (time to replenish O2 stores and eliminate CO2) of freely diving Steller sea lions. We also measured changes in breathing frequency of diving and non-diving individuals. Our findings show that hypercarbia increased breathing frequency (as low as 2 % CO2), but did not affect metabolic rate, or the duration of dives or surface intervals (up to 3 % CO2). Changes in breathing rates indicated respiratory drive was altered by hypercarbia at rest, but blood CO2 levels remained below the threshold that would alter normal dive behaviour. It took the sea lions longer to remove accumulated CO2 than it did for them to replenish their O2 stores following dives (whether breathing ambient air, hypercarbia, or hypoxia). This difference between O2 and CO2 recovery times grew with increasing dive durations, increasing hypercarbia, and was greater for bout dives, suggesting there could be a build-up of CO2 load with repeated dives. Although we saw no evidence of CO2 limiting dive behaviour, the longer time required to remove CO2 may eventually exhibit control over the overall time they can spend in apnoea and overall foraging duration.
Collapse
Affiliation(s)
- Carling D Gerlinsky
- Department of Zoology, University of British Columbia, 2202 Main Mall, Vancouver, BC, V6T 1Z4, Canada,
| | | | | |
Collapse
|
12
|
Lillie MA, Piscitelli MA, Vogl AW, Gosline JM, Shadwick RE. Cardiovascular design in fin whales: high-stiffness arteries protect against adverse pressure gradients at depth. J Exp Biol 2013; 216:2548-63. [DOI: 10.1242/jeb.081802] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SUMMARY
Fin whales have an incompliant aorta, which, we hypothesize, represents an adaptation to large, depth-induced variations in arterial transmural pressures. We hypothesize these variations arise from a limited ability of tissues to respond to rapid changes in ambient ocean pressures during a dive. We tested this hypothesis by measuring arterial mechanics experimentally and modelling arterial transmural pressures mathematically. The mechanical properties of mammalian arteries reflect the physiological loads they experience, so we examined a wide range of fin whale arteries. All arteries had abundant adventitial collagen that was usually recruited at very low stretches and inflation pressures (2–3 kPa), making arterial diameter largely independent of transmural pressure. Arteries withstood significant negative transmural pressures (−7 to −50 kPa) before collapsing. Collapse was resisted by recruitment of adventitial collagen at very low stretches. These findings are compatible with the hypothesis of depth-induced variation of arterial transmural pressure. Because transmural pressures depend on thoracic pressures, we modelled the thorax of a diving fin whale to assess the likelihood of significant variation in transmural pressures. The model predicted that deformation of the thorax body wall and diaphragm could not always equalize thoracic and ambient pressures because of asymmetrical conditions on dive descent and ascent. Redistribution of blood could partially compensate for asymmetrical conditions, but inertial and viscoelastic lag necessarily limits tissue response rates. Without pressure equilibrium, particularly when ambient pressures change rapidly, internal pressure gradients will develop and expose arteries to transient pressure fluctuations, but with minimal hemodynamic consequence due to their low compliance.
Collapse
Affiliation(s)
- M. A. Lillie
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - M. A. Piscitelli
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - A. W. Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - J. M. Gosline
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - R. E. Shadwick
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| |
Collapse
|
13
|
Xenon-Enhanced Dual-Energy CT of Patients With Asthma: Dynamic Ventilation Changes After Methacholine and Salbutamol Inhalation. AJR Am J Roentgenol 2012; 199:975-81. [DOI: 10.2214/ajr.11.7624] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
14
|
Hooker SK, Fahlman A, Moore MJ, de Soto NA, de Quirós YB, Brubakk AO, Costa DP, Costidis AM, Dennison S, Falke KJ, Fernandez A, Ferrigno M, Fitz-Clarke JR, Garner MM, Houser DS, Jepson PD, Ketten DR, Kvadsheim PH, Madsen PT, Pollock NW, Rotstein DS, Rowles TK, Simmons SE, Van Bonn W, Weathersby PK, Weise MJ, Williams TM, Tyack PL. Deadly diving? Physiological and behavioural management of decompression stress in diving mammals. Proc Biol Sci 2012; 279:1041-50. [PMID: 22189402 PMCID: PMC3267154 DOI: 10.1098/rspb.2011.2088] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 11/28/2011] [Indexed: 11/19/2022] Open
Abstract
Decompression sickness (DCS; 'the bends') is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N(2)) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N(2) tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N(2) loading to management of the N(2) load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.
Collapse
Affiliation(s)
- S K Hooker
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Vázquez-Medina JP, Zenteno-Savín T, Elsner R, Ortiz RM. Coping with physiological oxidative stress: a review of antioxidant strategies in seals. J Comp Physiol B 2012; 182:741-50. [PMID: 22327141 DOI: 10.1007/s00360-012-0652-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/25/2012] [Accepted: 01/28/2012] [Indexed: 12/30/2022]
Abstract
While diving, seals are exposed to apnea-induced hypoxemia and repetitive cycles of ischemia/reperfusion. While on land, seals experience sleep apnea, as well as prolonged periods of food and water deprivation. Prolonged fasting, sleep apnea, hypoxemia and ischemia/reperfusion increase oxidant production and oxidative stress in terrestrial mammals. In seals, however, neither prolonged fasting nor apnea-induced hypoxemia or ischemia/reperfusion increase systemic or local oxidative damage. The strategies seals evolved to cope with increased oxidant production are reviewed in the present manuscript. Among these strategies, high antioxidant capacity and the oxidant-mediated activation of hormetic responses against hypoxia and oxidative stress are discussed. In addition to expanding our knowledge of the evolution of antioxidant defenses and adaptive responses to oxidative stress, understanding the mechanisms that naturally allow mammals to avoid oxidative damage has the potential to advance our knowledge of oxidative stress-induced pathologies and to enhance the translative value of biomedical therapies in the long term.
Collapse
Affiliation(s)
- José Pablo Vázquez-Medina
- School of Natural Sciences, University of California Merced, 5200 N Lake Road, Merced, CA 95343, USA.
| | | | | | | |
Collapse
|
16
|
Cardiorespiratory pattern of rest-associated apnea in a Weddell seal: a case study at an ice hole in Antarctica. Polar Biol 2011. [DOI: 10.1007/s00300-011-1140-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
17
|
|
18
|
Piscitelli MA, McLellan WA, Rommel SA, Blum JE, Barco SG, Pabst DA. Lung size and thoracic morphology in shallow- and deep-diving cetaceans. J Morphol 2010; 271:654-73. [DOI: 10.1002/jmor.10823] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|